Characteristics of adsorption and biodegradation of dissolved organic carbon in biological activated carbon pilot plant

The dissolved organic carbon (DOC) properties for the influent of the BAC pilot plant have shown a 42% biodegradable fraction and a 58% non-biodegradable fraction. The biodegradable dissolved organic carbon (BDOC) was degraded entirely by biodegradation; the removal efficiency was 65–83%. The BDOC removal efficiency at empty bed contact time (EBCT) 15 minutes was larger than at EBCT 8 minutes. At increasing EBCT, a more slowly biodegradable fraction of BDOC (H₂) was utilized. The non-biodegradable dissolved organic carbon (NBDOC) was removed mostly by adsorption, and the removal amount was 24–58%. Therefore, the DOC was removed by adsorption and biodegradation; the removal efficiency by biodegradation was 31%, and that by adsorption was 24%. The breakthrough behaviors of DOC and NBDOC continued to be saturated as the bed volume increased, whereas the BDOC breakthrough curves maintained a certain ratio according to the bed volume.